Triphenylborane in Metal-Free Catalysis

Area of Science:

• Organic Chemistry
• Catalysis
• Polymer Science

Background:

• Organoboron reagents have gained prominence as Lewis acids in synthesis and metal-free catalysis.
• Triphenylborane (BPh3), a simple Lewis acid discovered a century ago, is being re-evaluated for modern catalytic applications.

Purpose of the Study:

• To review the recent catalytic applications of triphenylborane (BPh3) as a metal-free catalyst.
• To showcase the underexplored potential of BPh3 in various organic transformations.

Main Methods:

• Literature review of BPh3-catalyzed reactions.
• Focus on polymer synthesis, frustrated Lewis pair (FLP) chemistry, reductive methylations, cycloadditions, and insertion reactions.

Main Results:

• BPh3 catalyzes the copolymerization of epoxides with CO2, isocyanates, and anhydrides into various polycarbonate copolymers and polyurethanes.
• BPh3 functions as a Lewis acid in FLP-mediated hydrogen cleavage and hydrogenation catalysis.
• BPh3 effectively catalyzes reductive N- and C-methylations using CO2 and silanes, as well as cycloaddition and insertion reactions.

Conclusions:

• Triphenylborane (BPh3) is a highly versatile and commercially available catalyst for a wide range of metal-free organic transformations.
• The catalytic potential of BPh3 in synthesis and catalysis remains significantly underexplored.
• BPh3 offers a sustainable alternative to metal catalysts in various chemical processes.